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Sunday Sensational Science

“Pluto Had it Coming.” Neil deGrasse Tyson does science at Seattle’s Town Hall

When I’m old and gray and suffering from Alzheimer’s, I’ll still remember this lecture. Lecture? Can you call what amounts to stand-up comedy routine by so dry a word as lecture? I think not. It’s like calling Pluto a planet – it lumps Neil in with pompous pontificators, and doesn’t even begin to describe reality.

Did I think it would be interesting? Yes, I’m a bit of a closet science geek.

Did I think it would be entertaining? Yes, Tyson is animated and enthusiastic about the universe, enough to make him a regular guest on programs like the Daily Show with Jon Stewart and the TODAY Show.

Did I think we would be practically rolling on the floor laughing? No, and boy was I wrong.

That’s about how I felt. I figured the lecture would be interesting, informative, and at least a little entertaining, but I really didn’t expect the rib-fracturing hilarity. If all popularizers of science were this outrageously fun, we wouldn’t have to worry about a damn thing. American Idol and its ilk would be reduced to competing for time slots with infomercials at three in the morning. And science wouldn’t just be for geeks anymore.

The photo below captures some of Neil’s dynamism as a speaker. If you view lectures as an opportunity to catch up on sleep, you’re out of luck.

So, can someone who fills his lectures with anecdotes of death threats, zingers, one-liners, and political snark really educate you about science? Oh, yes he can!

Neil’s plugging his book The Pluto Files, which I had absolutely no interest in reading until now. When all the drama happened over ZOMG THEY DEMOTED PLUTO!1!!!1!! Planet, dwarf planet, my first and eleventy-first thoughts were “what-the-fuck-ever. Yawn.” Not yawning anymore.

This stuff is important. You’ll see why once we’ve reached the end of this series.

Neil began by setting the stage. Back around 2000 or so, when they were spiffing up the Hayden Planetarium, they were looking for different ways to present the solar system. Instead of the usual lineup, they decided to group like with like, creating a “family photo of the solar system,” as Neil described it. They put together the portraits: terrestrial planets, the asteroid belt, gas giants, Kuiper objects. And as they assembled the photos of various family members, they realized something: Pluto didn’t really fit with the terrestrial planets at all. It was small, icy, with an incredibly odd orbit. Where to put it?

Well, they had the Kuiper objects just sitting there staring at them. Imagine Neil leaning into the audience, sharing the process of dawning realization with suitably dramatic delivery: “Small – kinda like Pluto. Icy – kinda like Pluto. Odd orbits – kinda like Pluto.” No use trying to escape inescapable conclusions. Into the Kuiper objects Pluto went.

Neil received one letter about it over the next year, from a young boy named Will G. “You are missing planet Pluto,” Will wrote. “This is what it looks like.” He helpfully included a blue crayon drawing of Pluto. Priceless. And Neil, of course, milks that letter for all its comedic worth.

The point he and his colleagues at the Hayden Planetarium were making was this: “The name of the fifth planet from the sun – that’s not science.” In the best traditions of another Neil (Gaiman), they were being contentious, shaking things up. They were moving away from facts and getting into science.

Only Will G. really noticed. Until one year later, when the New York Times ran a story on its front page. January 22nd, 2001, Neil arrived to a full voicemail box and overflowing emails. “Something is awry,” he said, and picked up the Times.

On page one, sharing space with dimpled chads in Florida and a (now-debunked) story about Iraq rebuilding weapons, there was a headline:

Pluto Not a Planet

With all of the drama going on in the world, the Times had chosen to highlight the Hayden Planetarium’s demotion of Pluto. “Only in New York!” Neil milks this for it’s full dramatic effect. Apparently, all it takes for science to get front-page treatment is to redefine the solar system.

“That’s when the hate mail began,” Neil said. Pissed-off kids wrote him demanding him to put Pluto back. But of course, Neil and his fellow astrophysicists weren’t about to do that. Pluto’s demotion had been in the works for a long time. “Pluto had it coming.”

Neil loves throwing down on Pluto, but he also makes another excellent point: “Pluto had finally found family, and we think it’s happier there.” To understand why, it helps to know a little about the Kuiper Belt, and about another demoted planet.

This illustration makes it clear: Pluto really has found its family among Kuiper Belt objects. The Kuiper Belt itself is a region out beyond Neptune, where no planet large enough to sweep its orbit clean has formed. It vaguely resembles the asteroid belt – a lot of detritus left over from the formation of the solar system. But unlike the asteroid belt, it’s bodies aren’t rocky, but composed largely of frozen methane, ammonia and water. If Pluto got knocked out of its orbit (a distinct possibility in such a crowded place), and ended up swinging close to the Sun, it would develop a tail just like a comet. Did you know that? I didn’t – not before Neil.

I also didn’t know that when you describe Kuiper Belt objects as “icy bodies” around young children, you might get the reaction Neil once did: a shocked gasp, and a whispered, “Are there really dead bodies out there?”

Pluto’s not the first planet to get a demotion. Back in 1801, the astronomical world was abuzz with excitement. William Herschel had discovered Uranus – “Yur-in-iss, that’s how you pronounce that word” – and, based on a now-disproved law called the Titius-Bode law, astronomers began eagerly searching for a new planet they knew had to be there. On New Year’s Day in 1801, Giuseppe Piazzi found it, and named it Ceres.

Ceres ended up in textbooks as a planet for the next fifty years. But you won’t find Uranus there – unless you’re looking for George. Herschel had named it for the King of England. “I find the concept of a planet named George disturbing,” Neil told us. So did the rest of the astronomical world. But you can’t piss off Great Britain. Eventually, a compromise was reached: George was renamed Uranus, but instead of its moons being named after Greek gods, they were named after Shakespearean characters instead. This is the sort of thing that happens when astronomy runs headlong into international politics.

The Roman pantheon (after which all planets are named) is big, but possibly not big enough to contain all of the “planets” being discovered. By 1820, there were 11; shortly after, another dozen joined the crowd. Astronomers realized something was awry. These erstwhile planets were so tiny they appeared as pinpricks of light in telescopes. Eventually, in 1850, astronomers gave up calling them planets and classified them as asteroids – starlike, after their appearance in telescopes – instead.

When you compare Ceres to other planets in the Solar System, the reason for its demotion becomes crystal clear:

(Image filched from here; links to Bad Astronomy where I first saw it. Both sites commend your attention.)

If your vision is good, you might see the specks that represent the relative sizes of Ceres, Pluto, and fellow Kuiper Belt object and planetary contender Eris (2003 UB313). Important objects they are: planets, they are not.

But the search for planets wasn’t over. Newton’s laws of gravity described planetary orbits to a T, but the math just wouldn’t compute for Uranus. There were only two explanations: either there was another large body out beyond Uranus, or Newton’s laws didn’t work that far from the Sun. “That was the question of the day,” Neil says. They honestly didn’t know. But they crunched the numbers, predicted where a planet should be, and had a look – and there they found Neptune, right where Newton’s laws said it would be.

This will eventually take us to the discovery of Pluto, its rise and its fall. But we’re going to save that tale for next week. Neil packs a lot of science and a lot of history into a half-hour presentation. There’s no way I can do his delivery justice in prose – I’d have to be dancing across a stage like a Hindu god while delivering one-liners like a veteran comedian – but I can at least spend the time to do the science justice. And yes, we’ll be seasoning it liberally with Neil’s words o’ wisdom.

In the meantime, I’ve embedded a video clip of Neil that does a rather good job of capturing his wit, wisdom and wildness. This is actually something discussed at the lecture: Neil has endless fun with the doomsday crowd predicting the end of the world (again) in 2012. I’ll have even more for you next week – clear your calendars.

The quotes I’ve thrown in and the video I’ve included must have convinced you that Neil deGrasse Tyson is the most awesome science popularizer in the country. Should you ever get the chance to see him in person, do it. It doesn’t matter if you have to sell your firstborn, lie to your boss, or risk a relationship to get the night free. Every lover of science needs to see Neil at least once.

Drag along a disinterested friend. I guarantee that friend won’t stay disinterested for long. And by the end, even the most passionate Pluto partisans among us may forgive Neil for demoting it.